The broad, long-term objectives of this grant proposal are to understand the molecular mechanisms of genetic risk factors associated with chronic hereditary pancreatitis in humans. The studied genetic alterations include mutations of the cationic trypsinogen (PRSS1) and pro-carboxypeptidase A1 (CPA1). The research design combines biochemical and cell biological approaches with data obtained from human genetic association studies to formulate a disease model that can explain the higher susceptibility of mutation carriers to chronic pancreatitis. We hypothesize that genetic risk in chronic pancreatitis is mediated via two independent pathological pathways, both of which can result in acinar cell damage and death. In the trypsin-dependent pathological pathway intracellular autoactivation of trypsinogen to active trypsin causes acinar cell apoptosis;whereas in the misfolding-dependent pathological pathway retention of misfolded mutant proenzymes induces endoplasmic reticulum stress, which can trigger apoptotic cell death. In the next funding period, the following specific aims will be studied. (1) Acinar cell damage caused by intracellular autoactivation of cationic trypsinogen (PRSS1) mutants;(2) Misfolding of cationic trypsinogen (PRSS1) mutants and endoplasmic reticulum stress (3) Analysis of the enzymatic and cellular effects of novel CPA1 mutations associated with chronic pancreatitis. PUBLIC HEALTH RELEVANCE: The present grant proposal investigates how gene mutations in digestive enzymes cause hereditary pancreatitis, an inherited, progressive inflammatory disease of the pancreas. Results from this study can advance the development of novel diagnostic and therapeutic interventions for all forms of human pancreatitis.